Simultaneous pumping and density-selective particle focusing using AC-driven electro-osmotic micropumps

In this contribution we present a novel concept of density-selective particle focusing in microchannels, based on the tunable ratio of viscous drag, inertial and dielectrophoretic forces. The latter are induced by arrowhead-shaped, stepped electrode arrays in the channel, which, driven by AC voltages, enable so-called 3D-AC-electro-osmotic pumping (3D-ACEO). By adjusting the operation parameters of the pump, particle mixtures can be pumped and separated at the same time.